Model of the Robustness of Road Network-case of Madagascar.pdf

1、This is the first study which took the complex network approach to deal with road networking in Madagascar. Modeling the national road networking as a whole allowed us to inquire specificities inherent to the network suc

2、h as route and city classification, network robustness, transition phase and percolation. Madagascar's road network has vulnerability in the sense that the weak national infrastructures are frequently challenged by natur

3、al disasters. Questions arise about how strong the current network is to stand against those challenges and how far will it be able to maintain its integrity and its ability to serve the national economy. To measure the

4、robustness of the national road network, intercity road connections are modeled as a Poisson random network. The model contains 171 nodes representing cities and 251 road connections taken from the official island road m

5、ap. A random graph model with a degree distribution=2.93 has been obtained for the study of network resilience. Natural vulnerability is as a random attack on the network. Tests of network resilience under coordinated

6、 attack follows three strategies stemming from the centrality importance of the nodes: i) degree, ii) closeness, and iii) betweenness centrality. Results show higher vulnerability against targeted attacks compared to ran

7、dom failures. The betweenness-based strategy turns out have the most devastating effect on the network. Besides, Geographic road network is a particular case of random network in which links among nodes are under geograp

8、hic constraints;node positions are frozen on the space and the space itself is bounded by real geographic border. The second part of the study is dedicated on the phase transition of the road network by using the random

9、network model of Madagascar’s road network. Monte Carlo method is used to study the site percolation of the network on the projected map of the country. The Gilbert disc model gives us the connection threshold radius for

10、 the network and the effect of the geographical connection range on the phase transition. We also note that for a certain range, the radius has a noticeable effect on the birth process of cluster that takes place inside